21093442 has 4 divisors (see below), whose sum is σ = 31640166. Its totient is φ = 10546720.

The previous prime is 21093437. The next prime is 21093451. The reversal of 21093442 is 24439012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 19971961 + 1121481 = 4469^2 + 1059^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5273359 + ... + 5273362.

Almost surely, 2^21093442 is an apocalyptic number.

21093442 is a deficient number, since it is larger than the sum of its proper divisors (10546724).

21093442 is a wasteful number, since it uses less digits than its factorization.

21093442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10546723.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 21093442 is about 4592.7597368031. The cubic root of 21093442 is about 276.3010175835.

The spelling of 21093442 in words is "twenty-one million, ninety-three thousand, four hundred forty-two".